<DIV class="section" id="nlp">
     <H1> Research Projects in Natural Language Understanding</H1>
     <UL>
      <LI>
         <H3 id="resources">
          What lexical wide coverage resources can do for parsing
         </H3>
         <P align="justify"> 
             With the availability of open online ontologies (such as 
             <A HREF="http://verbs.colorado.edu/~mpalmer/projects/verbnet.html">
             VerbNet</A> and <A HREF="http://wordnet.princeton.edu/">WordNet</A>)
             describing the use, 
             meaning and functions of words, an opportunity exists to enhance parser technology.
             We look to bring automated reasoning built on semantic 
             understanding to the processing of language.</P>
         <P>
         <A HREF="lexical-resources.php"> Project Home </A> <!--|
         <A HREF= "http://works.bepress.com/yuliya_lierler/subject_areas.html#Natural_Language_Understanding"> Publications</A>-->
         </P>
      </LI>
      <LI>
         <H3 id="textual">
          Textual inference
         </H3>
         <P align="justify"> 
          In the problem of recognizing textual entailment, 
          the goal is to decide, given a text and a hypothesis 
          expressed in a natural language, whether a human 
          reasoner would call the hypothesis a consequence of 
          the text. One approach to this problem is to use a 
          first-order reasoning tool to check whether the 
          hypothesis can be derived from the text conjoined with 
          relevant background knowledge, after expressing all of 
          them by first-order formulas. Another possibility is 
          to express the hypothesis, the text, and the background 
          knowledge in a logic programming language, and use a 
          logic programming system. We explore the relation of 
          these methods to each other as well as new 
          possibilities for applying symbolic based methods for 
          the task of textual inference.
         </P>
         <P>
         <A HREF= "http://works.bepress.com/yuliya_lierler/subject_areas.html#Textual_Inference"> Publications</A>
         </P>
      </LI>
      <LI>
       <H3 id="copa">
        Causality in Natural Language Understanding
       </H3>
         <P align="justify"> 
          <a href="http://people.ict.usc.edu/~gordon/copa.html">Choice of Plausible Alternatives (COPA)</a> 
          is a commonsense causal reasoning challenge proposed in 2011. Given an utterance (a) <em>The shirt 
          shrunk.</em> Decide whether an utterance <em>I poured bleach on it</em> or 
          <em>I put in the dryer.</em> is the cause 
          for (a). This challenge targets two areas of research in Artificial Intelligence: natural 
          language processing and knowledge representation and reasoning. We are interested in exploiting 
          knowledge representation and reasoning techniques in identifying solution to this challenge.  
        </P>
      </LI>
      <LI>
       <H3 id="declarative">
        Syntactic Parsing by Means of Declarative Programming
       </H3>
        <P align="justify"> 
         Combinatory categorical grammar is one of the grammar formalisms 
         used for natural language parsing. This grammar assigns structured 
         lexical categories to words and uses combinatory rules to combine 
         these categories to parse a sentence.  We explore a new approach 
         to parsing that relies on a prominent knowledge representation 
         formalism, answer set programming -- a declarative programming 
         paradigm. Compared to other approaches, there is no need to 
         implement a specific parsing algorithm using such a declarative 
         method. Rather, a programmer encodes the specifications about the 
         combinators of the grammar. This approach is implemented in a 
         parsing tool kit called AspCcgTk that is a wide-coverage natural 
         language parser.
        </P>
        <P>
         <A HREF="http://www.kr.tuwien.ac.at/staff/former_staff/ps/aspccgtk/">Project Home</A> |
         <A HREF="http://works.bepress.com/yuliya_lierler/subject_areas.html#Syntactic_Parsing_by_Means_of_Declarative_Programming">Publications</A> |
         <A HREF="http://www.kr.tuwien.ac.at/staff/former_staff/ps/aspccgtk/">Software</A>
        </P>
       </LI>
      <LI>
         <H3 id="wsc">
          Coreference Resolution: Winograd Schema Challenge
         </H3>
         <P align="justify"> 
          The <A HREF="http://www.cs.nyu.edu/davise/papers/WS.html">
          Winograd Schema Challenge </A> is composed of
          instances of coreference resolution problems that prove to be 
          difficult for modern natural language processing methods. Ability 
          to perform commonsense inference seems to be the key in tackling 
          this challenge. An approach that takes commonsense reasoning into 
          account is the focus of this project. 
         </P>
      </LI>
     </UL>
</DIV>
